The field of the invention is truck bodies, and the invention relates more specifically to enclosed truck bodies which may either be mounted on the truck frame or on a separate trailor.
Most truck bodies have a welded steel or riveted aluminum structure which supports a relatively thin aluminum siding and top. Often an inner plywood wall or wooden slats are added to protect the thin aluminum surface from damage resulting from sources such as shifting cargo.
Although various attempts have been made to use structurally strong sidewall panels, most such attempts have failed because of numerous practical difficulties. The use of various joining elements typically results in water leakage because of the bowing or bending of the joining elements. This bowing or bending results from the movement of adjacent panels as a result of loading or as a result of the slight movement which results when a loaded truck goes over a bump in the road. Thus, the use of typical joining methods which may be perfectly satisfactory in a stationary building have proved unsatisfactory when tried in trucks. Any joining method, in order to be successful, must permit a certain amount of movement without bowing or springing so that the joint between adjacent panels will remain watertight. Similarly, the method for holding such panels at the bottom must also permit a certain amount of movement and remain watertight. The top joining method is somewhat less critical since water tends to run down and away from the upper joint. The corner joints like the panel joining rails are very critical and must provide a watertight seal in spite of the slight amount of movement that occurs during use.